1. Field of the Invention
The invention relates to a short optical disk drive, and in particular to a short optical disk drive with a vertical anti-tilt tray.
2. Brief Discussion of the Related Art
FIG. 1A is a perspective view of a conventional optical disk drive. In FIG. 1A, the conventional optical disk drive 10 has a main body 11 and a tray 12. The tray 12 has a recess 13 receiving optical discs. The main body 11 of the optical disk drive 10 has a carrier 14 and a driving module 17. A spindle motor 15 and a pickup head 16 are disposed on the carrier 14. After the driving module 17 moves the tray 12 holding an optical disc into the main body 11 and lifts the carrier 14, the spindle motor 15 rotates the optical disc, and data is read therefrom or written thereto by the. pickup head 16.
FIG. 1B shows a conventional optical disk drive with the tray ejected. In FIG. 1B, the main body 11 of the optical disk drive comprises two fulcrums 18 and top protrusions 19 in the front on either side, guiding the tray 12 along track 121. The main body 11 and tray 12 of the conventional optical disk drive comprises a length requiring that a large portion of the tray 12 remain in the main body 11 when the tray 12 is open. The top protrusions 19 can be disposed internally, such that the horizontal distance d between each top protrusion 19 and fulcrum 18 is longer, preventing obvious vertical tilt when the tray 12 is ejected.
Currently, optical disk drives are shortened to reduce required space in device housings. FIG. 2A shows a conventional short optical disk drive. Because the main body 21 and the tray 22 of the conventional short optical disk drive 20 are shortened, only a short portion of the tray 22 remains in the main body 21 when the tray 22 is open. The top protrusions 29 are close to the front edge of the main body 21, providing sufficient support for the tray 22. The horizontal distance d′ between each top protrusion 29 and fulcrum 28, however, is shortened as shown in FIG. 2B, such that the ratio of the first horizontal distance d′ between the top protrusion 29 and the fulcrum 28 to the second horizontal distance D between the fulcrum 28 and a front end of the tray 22 is larger than that in the conventional long optical disk drive 10 in FIG. 1A. Thus, gaps between the tray 22 and the top protrusions 29 are increased, causing the tray 22 to tilt seriously downward as shown by arrow p in FIG. 2B, with increased jitter and noise when closing the tray 22.